U.S. patent application number 10/861208 was filed with the patent office on 2005-02-17 for methods and apparatus for minimally invasive transverse aortic banding.
Invention is credited to Hu, Ping, Litwin, Sheldon E., Swenson, LeAnne, Zhang, DongFang.
Application Number | 20050038450 10/861208 |
Document ID | / |
Family ID | 34138529 |
Filed Date | 2005-02-17 |
United States Patent
Application |
20050038450 |
Kind Code |
A1 |
Hu, Ping ; et al. |
February 17, 2005 |
Methods and apparatus for minimally invasive transverse aortic
banding
Abstract
A curved suture applicator is provided for facilitation of
ligation procedures in mammals. The said curved suture applicator
enables a surgeon to efficiently encircle a target tissue such as a
blood vessel with a suture or thread. A kit is also provided,
comprising the said curved suture applicator, an appropriate length
of suture or thread, and a suture manipulation device, such as a
pair of forceps. Furthermore, a minimally invasive ligation method
is provided that utilizes the said curved suture applicator and kit
to efficiently band the transverse aorta of small mammals. Such
banding is useful in studying and simulating the effects of left
ventricular hypertrophy as it relates to congenital heart
failure.
Inventors: |
Hu, Ping; (Salt Lake City,
UT) ; Zhang, DongFang; (Salt Lake City, UT) ;
Swenson, LeAnne; (Salt Lake City, UT) ; Litwin,
Sheldon E.; (Salt Lake City, UT) |
Correspondence
Address: |
TRASK BRITT
P.O. BOX 2550
SALT LAKE CITY
UT
84110
US
|
Family ID: |
34138529 |
Appl. No.: |
10/861208 |
Filed: |
June 3, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60475677 |
Jun 3, 2003 |
|
|
|
Current U.S.
Class: |
606/148 ;
606/139; 606/228 |
Current CPC
Class: |
A61B 17/12013 20130101;
A61B 2017/061 20130101; A61B 2017/0046 20130101; A61B 2017/0608
20130101; A61B 17/0483 20130101; A61B 2017/00349 20130101; A61B
2090/08021 20160201 |
Class at
Publication: |
606/148 ;
606/139; 606/228 |
International
Class: |
A61B 017/10; A61B
017/04; A61L 017/00 |
Goverment Interests
[0002] The United States government may have rights in the
invention pursuant to grants from the Department of Veterans
Affairs and the National Institute of Health (HL 52338-06,
U01-70525, T32HL7576, HL5807).
Claims
What is claimed is:
1) A curved suture applicator, comprising a handle and a suture
holding tubular member curved to facilitate presentation of a
length of suture around an anatomical structure in an animal.
2) The curved suture applicator of claim 1, wherein the suture
holding tubular member is encased by a soft flexible sheath.
3) The curved suture applicator of claim 2, wherein the soft
flexible sheath is longer than the suture holding element.
4) The curved suture applicator of claim 2, wherein the soft
flexible sheath is shorter than the suture holding element.
5) The curved suture applicator of claim 1, wherein the suture
holding tubular member is a hollow tubular member.
6) The suture holding element of claim 4, wherein the suture
holding tubular member further comprises a 10 to 130 degree
curve.
7) The curved suture applicator of claim 4, wherein the suture
holding tubular member further comprises a 50 degree curve.
8) The curved suture applicator of claim 4, wherein the suture
holding tubular member further comprises a 30 degree curve.
9) The curved suture applicator of claim 4, wherein the suture
holding tubular member further comprises two 30 degree curves.
10) The curved suture applicator of claim 4, wherein the suture
holding tubular member further comprises three 30 degree
curves.
11) The curved suture applicator of claim 4, wherein the suture
holding tubular member further comprises a 70 degree curve.
12) A curved suture applicator, consisting of: a suture holding
hollow tubular member having a proximal end and a distal end,
wherein the distal end is configured to receive a length of a
suture; a 50 degree curve proximal to the distal end to facilitate
presentation of the length of suture around an anatomical structure
in an animal; and a soft plastic sheath encasing the suture holding
hollow tubular member.
13) The curved suture applicator of claim 12, wherein the soft
flexible sheath is longer than the suture holding hollow tubular
member.
14) The suture holding tubular member of claim 13, wherein the soft
flexible sheath is slidably engaged to the suture holding hollow
tubular structure.
15) A kit for performing a minimally invasive ligation or
constriction procedure, the kit comprising: the curved suture
applicator of claim 4; and a length of suture.
16) The kit of claim 15, further comprising a suture manipulation
device.
17) The kit of claim 15, further comprising instructions.
18) The kit of claim 15, further comprising a spacer.
19) The kit of claim 15, further comprising an isolator tool.
20) The kit of claim 15, wherein the curved suture applicator
comprises a 50 degree curve.
21) A kit for performing a minimally invasive ligation or
constriction procedure, the kit consisting of: the curved suture
applicator of claim 12; a length of suture; a suture manipulation
device; and instructions.
22) A minimally invasive ligation method for disposing a length of
suture around an anatomical structure of an animal, comprising:
inserting the curved suture applicator of claim 4 into the body of
an animal, wherein the suture holding tubular member carries a
length of suture through an incision in the animal; passing the
curved applicator having the suture under an anatomical structure
in the animal; manipulating the suture so as to encircle the
anatomical structure of the animal; disposing a spacer proximate to
the anatomical structure; tying the encircling length of suture
around the anatomical structure and the spacer; and removing the
spacer.
23) The minimally invasive method of claim 22, wherein the animal
is a mammal.
24) The minimally invasive method of claim 23, wherein the
anatomical structure to be encircled is an aorta, and the mammal is
a small mammal.
25) The minimally invasive method of claim 24, wherein inserting
the curved suture applicator does not breach the mammal's pleural
space.
26) The minimally invasive method of claim 25, further comprising
forming a small incision in the mammal's sternum and inserting the
curved suture applicator through the incision in the small mammal's
sternum.
27) The minimally invasive method of claim 26, wherein the small
mammal is a mouse.
28) The minimally invasive method of claim 23, wherein the small
mammal is a mouse.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit under 35 U.S.C. .sctn.
119(e) of U.S. Provisional Application No. 60/475,677, filed Jun.
3, 2003, which is incorporated herein by reference.
TECHNICAL FIELD
[0003] The present invention relates generally to biotechnology,
more specifically, to ligation surgical techniques and a surgical
apparatus. The present invention relates to minimally invasive
methods and apparatus for vesicle constriction.
BACKGROUND
[0004] Procedures for ligating tissues in surgical operations are
frequently performed. Generally, ligation may take the form of a
constricting band composed of a thread or suture. The thread or
suture is passed around the target vessel and then tied into a
constricting band. The knot-tying process may occur either inside
(intracorporeal ligation) or outside (extracorporeal ligation) the
body. Ligation of a vessel may also be achieved via use of a clip
or staple.
[0005] Extracorporeal ligation is generally performed in the
following manner. A thread (suture) is passed under a tissue of
interest (i.e., a tissue for which the operational work is done).
Then, both ends of the thread are drawn out of the subject's body
and a knot is formed outside the body. The knot is put into the
body by means of a thread feed instrument called a "knot pusher" or
"knot driver," which acts to tighten the knot. Generally, a square
knot is used because it is not easily loosened.
[0006] In intracorporeal ligation, the knot is formed by using two
forceps or other suture-holding devices inserted into the body
cavity and the knot is formed inside the subject's body. Once
again, a square knot is generally formed.
[0007] In both intra- and extracorporeal ligation, at least three
primary difficulties must be overcome. First, the thread or suture
must be passed around the vessel or tissue of interest. In certain
surgeries, particularly in small animals, operational space may be
very limited. Second, threading a suture around an object can
require significant experience and/or be very time consuming.
Again, if space is limited, tying the knot intracorporeally can be
very challenging. Finally, ligation operations should not cause
excessive damages to the regions being operated.
[0008] The ligation technique utilizing a clip or staple is
advantageous in that the time-consuming knot-tying work required
for extracorporeal ligation and intracorporeal ligation may be
omitted. However, using this technique may require a more expensive
apparatus for performing the ligation. Additionally, because
foreign matter such as a clip may be left in the body, the range of
application of this technique is limited.
[0009] With regards to intra- and extracorporeal ligation methods,
several prior art devices are in existence to help overcome the
challenges of passing and tying a thread around a tissue. However,
many such devices do not allow the operator to pass a thread or
suture around the tissue without first cutting through it.
Furthermore, those devices that do not require initial cutting are
generally complex, expensive, and usually require a large opening
or port for inserting the device.
[0010] Such ligation devises are often used in the ligation or
constriction of vessel-like membranes in mammals. One example of a
procedure that involves ligation or constriction, is transverse
aortic banding of small mammals, such as rats, mice, or guinea
pigs. Constriction of the aorta has been used for many years to
produce pressure-overload hypertrophy in small mammals, such as
rodents, thus allowing researchers to study the causes of
congenital heart failure. Generally, a constricting band is placed
between the branches of the right and left carotid arteries. In
order to access the aorta, the chest is entered in the second
intercostal space at the left upper sternal border through a small
incision. Then, aortic ligation is achieved by tying a nylon or
silk suture ligature around the aorta and an accompanying blunt
needle, which acts as a spacer to determine the scope of the
constriction. When the needle is pulled out from within the suture
loop, only the aorta remains within the constricting band. The
result is that the aorta may be narrowed, for example, in mice the
aorta is often constricted to about 0.4 mm in diameter, to produce
a transverse aortic constriction ("TAC") of 65-70%. However, one
limitation to this particular example of a constriction protocol is
that it causes a breach of the pleural space and necessitates
mechanical ventilation of the mammal. The use of mechanical
ventilation requires additional time, expertise and equipment.
Moreover, inflammatory reactions within the chest may complicate
the analyses of cardiac function and pathology.
[0011] In view of the foregoing discussion of ligation devices
generally, and of ligation methods as applied to a tubular vessel,
such as mammalian aortas, there is a need in the art for improved
ligation devices and methods.
SUMMARY OF THE INVENTION
[0012] The apparatus and/or methods of the invention may be applied
to the constriction or ligation of a tubular vessel or other
like-anatomical structure.
[0013] The invention provides an apparatus that is herein referred
to as a curved suture applicator, whose purpose is to aid in the
positioning of a thread or suture around a target tissue so that
the thread or suture may be used to ligate or constrict the
tissue.
[0014] The invention also provides a curved suture applicator
comprising a hollow and/or solid tubular member. The distal end of
the tubular member comprises a passage adequate for holding or
passing a portion of a thread or suture. The tubular member
comprises a straight portion and a bent or curved portion disposed
at the distal end of the tubular member, thus allowing the distal
end of the tubular member to be passed under the target tissue and
thereby present an attached thread or suture in an accessible
manner on the distal side of the target tissue.
[0015] The invention further provides a tubular member that may be
covered by a soft flexible material or sheath, such as a plastic,
rubber, Teflon.RTM. and other like materials which prevent or
reduce abrasion of tissues within a subject. The invention further
provides a soft flexible material that is slidably engaged to at
least the tubular member.
[0016] The invention also provides a method for a minimally
invasive ligation procedure, facilitating ligation or constriction
of a vesicular membrane. When used in combination with a suture
manipulation device such as a pair of forceps, the curved suture
applicator is used to easily dispose a silk or nylon suture around
a mammalian vesicle. Where appropriate, a predetermined
constriction may be achieved by placing a spacing apparatus
substantially parallel to the target vesicle. The suture is then
tied, creating either a ligation or a constricting band around the
vesicle.
[0017] An exemplary embodiment of the present invention is a
transverse aortic banding ("MTAB") procedure in mammals, utilizing
the above-mentioned curved suture applicator. The MTAB method
obviates the need for providing mechanical ventilation to the
mammal because the pleural cavity of the mammal is not entered.
Instead, access to the aorta is achieved by inserting the curved
suture applicator through an incision in the mammal's sternum. When
used in combination with a suture manipulation device such as a
pair of forceps or a hooking devise, the curved suture applicator
is used to easily dispose a suture around the mammalian aorta. A
spacing apparatus, such as a blunt needle of a predetermined size
is placed substantially parallel to the mammalian aorta and the
suture is then tied, creating a constricting band around the aorta,
thus inducing pressure-overload in the heart.
[0018] The present invention also includes a kit comprising a
curved suture applicator that allow for the placement of a suture
around an anatomical object. Optionally, the kit may contain one or
more protective soft flexible materials that are adapted to cover
at least the distal tip of the curved suture applicator.
Optionally, the suture may be pre-loaded through the suture
applicator. Optionally, the kit may contain additional suture.
Optionally, suture kit may be sterilized via UV light or other
methods known in the art. Optionally, the kit may contain an
isolator consisting of rigid or semi-rigid member having a means
for assisting in the isolation of tube to be ligated. In addition,
the kit may be disposable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 depicts a curved suture applicator with an optional
soft flexible sheath covering the suture thread passage; the suture
thread has been introduced into and is held by the distal end of
the suture thread passage;
[0020] FIG. 2 depicts the curved suture applicator of FIG. 1, and
demonstrates how the optional soft flexible sheath may be removed
from the distal end of the suture thread passage in the hollow
tubular member;
[0021] FIG. 3 depicts the curved suture applicator of FIG. 1, with
the optional handle attached to the proximal end of the curved
suture applicator;
[0022] FIG. 4 depicts a curved suture applicator with the optional
soft flexible sheath covering the suture thread passage; the suture
thread has been introduced into the distal end of the suture thread
passage and threaded completely through the suture thread passage
so that it exits the proximal end of the curved suture
applicator;
[0023] FIG. 5 depicts a curved suture applicator whose distal end
is positioned underneath a mammalian aorta; a suture thread has
been threaded into the distal end of the suture thread passage, and
has been positioned by the curved suture applicator so as to be
easily accessed from above the aorta; and
[0024] FIG. 6 is a photograph of latex casts of aortas following
MTAB (left) and sham surgery (right). The silk ligature has been
removed from the MTAB aorta, but the site of narrowing is evident
(arrow demonstrates location of constriction).
DETAILED DESCRIPTION
[0025] The invention provides an apparatus and a method for
constricting or ligating a vesicle or tissue in a subject. The
curved suture applicator may be formed of a hollow and/or solid
tubular member of hard material, which may optionally be covered by
a softer material, such as plastic, rubber, silicon or Teflon.RTM.,
to help protect the tissues within a subject. A suture thread
passage for passing or holding a suture thread is formed at the
distal end of the tubular member. In one exemplary embodiment, the
inside diameter of a hollow tubular member is preferably greater
than the outside diameter of the suture thread, which is to be
inserted in the suture thread passage, thereby allowing the suture
to be passed through at least the hollow tubular member.
[0026] The tubular member comprises a straight portion and a bent
or curved portion disposed at the distal end of the tubular member.
The bend or curvature of the tubular member is configured so that
it may be passed under a vesicle and present the suture in an
accessible manner.
[0027] The device shown in FIG. 1 is an exemplary representation of
a curved suture applicator. There, an angio-catheter 20, with
distal end 41 and proximal end 42, was properly modified to include
a curved, suture-thread passage 21 whose dimensions were adequate
to position a suture around a mouse aorta. The suture thread
passage 21 (a 24-gauge needle) was dimensioned at 24.5 mm in length
and 0.7 mm in diameter. The silk suture 10 used was 6-0 suture
thread (which may have a diameter between about 0.07 and about
0.099 mm), thus the silk suture may be inserted into the tip of the
curved suture applicator, where it is held as the curved suture
applicator was inserted into a subject. The tip of the applicator
was bent at about a 50-degree angle, thus creating a curved suture
applicator that could be positioned underneath the target tissue,
allowing the held suture to be accessible from above the target
tissue.
[0028] The bent portion of the applicator may be positioned
relative to the distal tip 41 of the tubular member as is
appropriate for the diameter of the target tissue. For example, the
bend may be placed about 1.5 mm from the distal end of the tubular
member. Finally, a soft plastic sheath 31 may be slidably engaged
to the tubular member via the sheath connector 32 so as to avoid or
reduce any accidental piercings or abrasions within the thoracic
cavity during the procedure. In the case of the angio-catheter, the
sheath was at least 25 mm in length. Thus, in this exemplary
embodiment, the sheath covered the full length of the rigid hollow
tubular member and was slidably engaged with the hollow tubular
member, such that it could be extended from the curved end.
[0029] The exact dimensions shown in FIG. 1 are exemplary only. The
dimensions of the curved suture applicator will vary according to
the needs of the procedure. For example, it is envisioned that a
curved suture applicator may be configured with two or three
50-degree bends in the tip of the tubular member. As will be
apparent to a person of ordinary skill in the art, in light of the
present disclosure, when two or more bends are utilized each bend
may lie in the same plane or a different plane. Alternatively, one,
two, or even three 30, 35, 40, 45, 50, 55, 60, 65 and/or 70 degree
bends. For example, a single 70-degree bend in the tip of the
tubular member is envisioned. Multiple bends of 10-, 20-, 40-, or
60-degrees, or any combination thereof, may be incorporated. The
lengths of the unbent and bent tubular members may also vary
according to the needs of the procedure. Finally, the diameter of a
tubular member may vary, for instance, according to the diameter of
the suture to be used in a given procedure. For example, when the
suture is to be passed through the hollow tubular member, it is
desirable that the hollow tubular member have a greater diameter
than the diameter of the suture. Similarly, the diameter and length
of the optional soft flexible sheath may change to accommodate the
diameter and length of the tubular member.
[0030] In another exemplary embodiment shown in FIG. 2, the suture
10 is fastened to the end of the suture thread passage 21. For
example, the suture may be fastened to the end of a solid or semi
solid tubular member by slidably engaging a flexible sheath 31 such
that the suture is captured inside the tubular member or between
the tubular member, which is encased in the sheath, and/or the
suture may be passed through an aperture in the tubular member.
[0031] In an exemplary embodiment, the total length of the soft
flexible sheath, if desired, may be longer than the exposed length
of the tubular member. In another exemplary embodiment, a flexible
sheath or covering may be shorter than the exposed length of the
tubular member. In yet another exemplary embodiment, the flexible
sheath or covering is affixed to the distal end (or tip) of the
tubular member.
[0032] The tubular member may be configured to attach to a handle,
as in FIG. 3. In one exemplary embodiment the tubular member 20 is
attached to any of the connection devises known in the art (for
example, a luer fittings, threaded connection means, glue, or the
like), which facilitates the attachment of a handle or extension
devise 22 as are known in the art. The handle or extension devise
22 may comprise an endoscopic surgical system
[0033] The tubular member may be made of a variety of hard
materials. Various plastics or metals will suffice, preferably the
material used may be sterilized and is non-reactive with organic
material that it may come in contact with. The material used should
be relatively stiff and able to "hold" its position or shape, even
under moderate pressure. Similarly, the optional soft sheath may be
made of various, inert and flexible materials such as plastic,
rubber, silicon or Teflon.RTM..
[0034] Methods and materials which may be useful in forming or
constructing a tubular member, a flexible coating or sheath,
retaining devises, and suture manipulation devises are described in
U.S. Pat. Nos. 5,281,236; 5,702,407; 5,658,299; and 4,683,885, as
well as International Patent Publications WO 04/004577 and WO
97/003615, which the entirety of each is hereby incorporated by
reference.
[0035] A second embodiment of the curved suture applicator, as
shown in FIG. 4, comprises the same hollow tubular member 20 as
previously outlined, but now further comprises an opening on the
proximal end 42 of the tubular member. Thus, a suture thread 10
need not only be threaded into and held at the distal end 41 of the
tubular member, but it may also be passed through the hollow
tubular member 20 and secured at a site distal to the proximal end
42 of the hollow tubular member. For example, the suture may be
secured in a retaining means on a handle affixed to the hollow
tubular member, or outside of the patient's body. A length of
suture thread would still protrude from the distal end of the
hollow tubular member, thus allowing the curved suture applicator
to be positioned in such a way as to make the distal end of the
suture thread accessible for a ligation procedure. For example, a
suture passed through the hollow tubular member may be retained by
a retaining devise, such as a bobbin, hook, clasp or like
structure.
[0036] In an exemplary embodiment using the curved suture
applicator, as demonstrated in FIG. 5, a minimally invasive
technique for constricting a mammalian vesicle is provided. Upon
accessing the vesicle 50, a length of surgical silk or nylon suture
10 should be applied to the vesicle 50. The distal end 41 of the
curved suture applicator is inserted under the vesicle 50, thereby
presenting the suture 10 on the distal side of the vesicle. A
suture manipulation device, such as a pair of forceps, may be used
to bring the suture back away from the vesicle 50. A spacer, such
as a blunt 27-gauge needle, may then be placed next to the portion
of the vesicle to be constricted, allowing the silk or nylon suture
to be snugly tied about both the vesicle and the needle, either
extra- or intracorporeally. The spacer may then be slid out from
under the suture knot, leaving the vesicle constricted by the
suture (e.g., a silk or nylon suture) to a diameter equal to that
of the spacer used.
[0037] As will be apparent to a person of ordinary skill in the art
after reading the disclosure, the spacer may be of any size or
diameter appropriate to the desired constriction. Likewise, the
spacer may be made of any material that does not deform under the
pressure of the constricting suture. For example, the spacer may be
metal or plastic.
[0038] The invention may include an isolator, which may be used to
retract a tissue, organ, or vessel. An isolator may be a rigid or
semi-rigid member having a hook, or other devise or means at one
end, wherein the isolator facilitates the ability to grasp or
engage a tissue, organ or vessel. The isolator may be covered by a
soft material such as plastic, rubber or Teflon.RTM., so as to
further avoid the risk of accidental piercing of a tissue, organ or
vessel within the body.
[0039] In another exemplary embodiment, a minimally invasive
technique for constricting the transverse aorta in mice is provided
that does not require mechanical ventilation because the pleural
cavity is not breached (e.g., minimally invasive transverse aortic
banding (MTAB)). The present invention can be used to consistently
constrict the aorta in less than 10 minutes with rapid recovery and
low morbidity and mortality. Not only is the approach of the
present invention substantially faster and less expensive than
previous methods, but potentially confounding experimental factors
such as inflammation within the chest and healing of the chest wall
incision are reduced. The invention produces changes in left
ventricular size, function and expression of hypertrophic markers
(i.e., increased expression of atrial natriuretic factor (ANF) and
beta-myosin heavy chain) that are very comparable to those achieved
with the conventional surgical technique. The use of a technique
with lower mortality is particularly important, for example, when
studying the effects of pressure-overload in rare or precious lines
of genetically altered mice. The same ligation or constriction
technique may be applied to other tissues such as the kidney, lung,
stomach or muscle. Thus, the ligation or constriction technique may
be used to survey changes in gene expression that occur in response
(direct or indirect) to ligation or constriction of other vessels,
tissues or organs. For example, a kidney or a part of a kidney of a
subject may be constricted so as to facilitate the analysis of
genes induced by such ligation, constriction or even kidney damage.
Likewise, with other tissues, organs or vessels, such as the lung,
stomach, muscle, etc.
[0040] The MTAB technique, as embodied in the present invention,
may be applied to small mammals, such as mice, rats, and guinea
pigs. Prior to surgery, the experimental animal may, if appropriate
and desirable, be anaesthetized. The initial step of the MTAB
technique utilizes a 1.5-cm ventral midline incision, centered on
the clavicle of the small mammal to be used in the experiment.
Then, instead of accessing the aorta through an intercostal space,
access is created by cutting a 2- to 3-mm longitudinal cut in the
proximal portion of the sternum to the level of the second rib.
Behind the sternum are the lobes of the thymus. The two lobes of
the thymus should be divided, thus revealing the aortic arch as it
crosses the trachea. The stretch of the aorta between the
brachiocephalic and left carotid arteries should be isolated from
surrounding tissue by utilizing a hook-like device that can
effectively pull the aorta away from its neighboring tissue. Then a
length of surgical suture is applied by inserting the curved suture
applicator under and to the back of the aorta. A suture
manipulation device, such as a pair of forceps, may be used to
bring the suture back away from the aorta. A spacer, such as a
blunt 27-gauge needle, may then be placed next to the isolated
portion of the aorta, allowing the silk suture to be snugly tied
about both the aorta and the needle. The spacer is then be slid out
from under the suture knot, leaving the aorta constricted by the
suture to a diameter equal to that of the spacer. Finally, the
muscle and skin incisions may be closed using methods known in the
art. The results of an application of the MTAB technique are
demonstrated in FIG. 6. There, a heart with a constricted aorta 70
may be compared to a heart with an un-constricted aorta 80. The
constriction in heart aorta 70 is indicated by the arrow in the
figure.
[0041] The invention also provides a kit, which may be used to
perform the MTAB procedure or to facilitate any other related
tissue ligation or constriction procedure. Specifically, parts to
be included in the kit will facilitate the placement and tying of a
length of suture around an anatomical structure of a mammal. Such
parts may include the above-described curved suture applicator, an
appropriate length of suture (which may be either separate or
pre-threaded in the applicator), a suture manipulation device, such
as a pair of forceps or other clamping device, a spacer, a tool for
isolating the vessel, and/or a set of instructions for proper use
of the included curved suture applicator or protocol for performing
the MTAB procedure.
[0042] The kit and/or the curved suture applicator may be used in a
variety of surgical settings. The kit and/or curved suture
presentation device may be used on any small vessel or nerve
requiring constriction or ligation. Such needs occur in the
aforementioned aortic surgery procedure, as well as in related
pulmonary surgery. Similar uses may be found in reconstructive
surgery, any type of microsurgery, craniofacial surgery, cosmetic
surgery, and even hand surgery. Uses in gynecological and other
reproductive surgery may be envisioned. Also, where appropriate and
desirable, the kit and curved suture applicator may be used to
apply a suture around muscle and/or tendons.
EXAMPLE I
[0043] To further illustrate the present invention, consider once
again the use of the curved suture applicator in the aforementioned
MTAB technique. FIG. 1 is a photograph of latex casts of aortas
following MTAB (left) and sham surgery (right). The silk ligature
has been removed from the aorta, but the site of narrowing is
evident (arrow demonstrates location of constriction). Aortic
constriction, as shown in FIG. 1, and as performed by applying the
present invention, may be used to artificially simulate
hypertension, thus initiating a chain of events in the left
ventricle of the heart in response to the higher blood pressure.
Over a sufficient time period, the left ventricle of the affected
heart will begin to enlarge. It is this resulting left ventricle
hypertrophy that often leads to congenital heart failure. Thus, by
using the present invention to simulate left ventricular
hypertrophy, other studies and experiments may be conducted on the
hypertrophied heart to determine the nature and pathology of the
responsible gene signaling pathways or a signal transduction
cascade. Once identified, treatments for congenital heart disease,
for example, treatments that act to block the signaling pathways or
cascades causing left ventricular hypertrophy, may be
developed.
[0044] Although the present invention has been described with
respect to the illustrated embodiments, various additions,
deletions and modifications are contemplated as being within the
scope of the invention. The scope of the invention is, therefore,
indicated by the ensuing claims, rather than the foregoing
description. All changes that come within the meaning and range of
equivalency of the claims are to be embraced within their
scope.
[0045] All references presented herein using open terminology such
as, comprising and/or including, contemplates closed terminology,
such as consisting of and consisting essentially of.
[0046] All references, including publications, patents, and patent
applications, cited herein are hereby incorporated by reference to
the same extent as if each reference were individually and
specifically indicated to be incorporated by reference and were set
forth in its entirety herein.
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